Reapply revert script.

tools/revert.py

 #!/usr/bin/python
 
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 import optparse
 import os
 import platform
 import subprocess
@@ skipping 61 matching lines @@
     results, _ = run_cmd(['svn', 'st'])
   else:
     results, _ = run_cmd(['git', 'status'])
   for line in results.split('\n'):
     if not is_git and (not line.strip().startswith('?') and line != ''):
       return True
     elif is_git and ('Changes to be committed' in line or 
         'Changes not staged for commit:' in line):
       return True
   if is_git:
-    p = subprocess.Popen(['git', 'log', '-1'], stdout=subprocess.PIPE, shell=True)
+    p = subprocess.Popen(['git', 'log', '-1'], stdout=subprocess.PIPE,
+                         shell=(platform.system()=='Windows'))
     output, _ = p.communicate()
     if find_git_info(output) == None:
       return True
   return False
 
 def run_cmd(cmd_list, suppress_output=False, std_in=''):
   """Run the specified command and print out any output to stdout."""
   print ' '.join(cmd_list)
   p = subprocess.Popen(cmd_list, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                        stdin=subprocess.PIPE,
                        shell=(platform.system()=='Windows'))
   output, stderr = p.communicate(std_in)
   if output and not suppress_output:
     print output
   if stderr and not suppress_output:
     print stderr
   return (output, stderr)
 
 def runs_git():
   """Returns True if we're standing in an svn-git repository."""
   p = subprocess.Popen(['svn', 'info'], stdout=subprocess.PIPE,
-                       stderr=subprocess.PIPE, shell=True)
+                       stderr=subprocess.PIPE,
+                       shell=(platform.system()=='Windows'))
   output, err = p.communicate()
   if err != None and 'is not a working copy' in err:
-    p = subprocess.Popen(['git', 'status'], stdout=subprocess.PIPE, shell=True)
+    p = subprocess.Popen(['git', 'status'], stdout=subprocess.PIPE,
+                         shell=(platform.system()=='Windows'))
     output, _ = p.communicate()
     if 'fatal: Not a git repository' in output:
       maybe_fail('Error: not running git or svn.')
     else:
       return True
   return False
 
 def find_git_info(git_log, rev_num=None):
   """Determine the latest svn revision number if rev_num = None, or find the 
   git commit_id that corresponds to a particular svn revision number.
@@ skipping 66 matching lines @@
          user_input=True)
   if git_user:
     run_cmd(['git', 'cl', 'rebase'])
   run_cmd(['gclient', 'sync'])
   revert(revisions[0], revisions[1], git_user)
   print ('Now, create a CL and submit! The buildbots and your teammates thank '
          'you!')
 
 if __name__ == '__main__':
   main()